[PATCH] crypto: marvell/octeontx - prevent integer overflows

[PATCH] crypto: marvell/octeontx - prevent integer overflows

[Dan Carpenter]

The "code_length * 2" can overflow.  The round_up(ucode_size, 16) +
sizeof() expression can overflow too.  Prevent these overflows.

Fixes: d9110b0b01ff ("crypto: marvell - add support for OCTEON TX CPT engine")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
I chose INT_MAX because it's way higher than what kmalloc() can allocate
and it makes the code simpler.  I think there is a static checker which
tells people to change these to UINT_MAX.  Don't do that, or at least
CC me if you do.

 .../crypto/marvell/octeontx/otx_cptpf_ucode.c | 23 +++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/marvell/octeontx/otx_cptpf_ucode.c b/drivers/crypto/marvell/octeontx/otx_cptpf_ucode.c
index 23c6edc70914..1be85820d677 100644
--- a/drivers/crypto/marvell/octeontx/otx_cptpf_ucode.c
+++ b/drivers/crypto/marvell/octeontx/otx_cptpf_ucode.c
@@ -286,6 +286,7 @@ static int process_tar_file(struct device *dev,
 	struct tar_ucode_info_t *tar_info;
 	struct otx_cpt_ucode_hdr *ucode_hdr;
 	int ucode_type, ucode_size;
+	unsigned int code_length;
 
 	/*
 	 * If size is less than microcode header size then don't report
@@ -303,7 +304,13 @@ static int process_tar_file(struct device *dev,
 	if (get_ucode_type(ucode_hdr, &ucode_type))
 		return 0;
 
-	ucode_size = ntohl(ucode_hdr->code_length) * 2;
+	code_length = ntohl(ucode_hdr->code_length);
+	if (code_length >= INT_MAX / 2) {
+		dev_err(dev, "Invalid code_length %u\n", code_length);
+		return -EINVAL;
+	}
+
+	ucode_size = code_length * 2;
 	if (!ucode_size || (size < round_up(ucode_size, 16) +
 	    sizeof(struct otx_cpt_ucode_hdr) + OTX_CPT_UCODE_SIGN_LEN)) {
 		dev_err(dev, "Ucode %s invalid size\n", filename);
@@ -886,6 +893,7 @@ static int ucode_load(struct device *dev, struct otx_cpt_ucode *ucode,
 {
 	struct otx_cpt_ucode_hdr *ucode_hdr;
 	const struct firmware *fw;
+	unsigned int code_length;
 	int ret;
 
 	set_ucode_filename(ucode, ucode_filename);
@@ -896,9 +904,16 @@ static int ucode_load(struct device *dev, struct otx_cpt_ucode *ucode,
 	ucode_hdr = (struct otx_cpt_ucode_hdr *) fw->data;
 	memcpy(ucode->ver_str, ucode_hdr->ver_str, OTX_CPT_UCODE_VER_STR_SZ);
 	ucode->ver_num = ucode_hdr->ver_num;
-	ucode->size = ntohl(ucode_hdr->code_length) * 2;
-	if (!ucode->size || (fw->size < round_up(ucode->size, 16)
-	    + sizeof(struct otx_cpt_ucode_hdr) + OTX_CPT_UCODE_SIGN_LEN)) {
+	code_length = ntohl(ucode_hdr->code_length);
+	if (code_length >= INT_MAX / 2) {
+		ret = -EINVAL;
+		goto release_fw;
+	}
+	ucode->size = code_length * 2;
+	if (!ucode->size ||
+	    ucode->size > fw->size ||
+	    (fw->size < round_up(ucode->size, 16) +
+	     sizeof(struct otx_cpt_ucode_hdr) + OTX_CPT_UCODE_SIGN_LEN)) {
 		dev_err(dev, "Ucode %s invalid size\n", ucode_filename);
 		ret = -EINVAL;
 		goto release_fw;
-- 
2.35.1

Re: [PATCH] crypto: marvell/octeontx - prevent integer overflows

[Herbert Xu]

On Thu, Sep 01, 2022 at 06:32:09PM +0300, Dan Carpenter wrote:
>
> @@ -303,7 +304,13 @@ static int process_tar_file(struct device *dev,
>  	if (get_ucode_type(ucode_hdr, &ucode_type))
>  		return 0;
>  
> -	ucode_size = ntohl(ucode_hdr->code_length) * 2;
> +	code_length = ntohl(ucode_hdr->code_length);
> +	if (code_length >= INT_MAX / 2) {
> +		dev_err(dev, "Invalid code_length %u\n", code_length);
> +		return -EINVAL;
> +	}
> +
> +	ucode_size = code_length * 2;
>  	if (!ucode_size || (size < round_up(ucode_size, 16) +
>  	    sizeof(struct otx_cpt_ucode_hdr) + OTX_CPT_UCODE_SIGN_LEN)) {
>  		dev_err(dev, "Ucode %s invalid size\n", filename);

How come you didn't add a "ucode_size > size" check like you did
below?

> @@ -896,9 +904,16 @@ static int ucode_load(struct device *dev, struct otx_cpt_ucode *ucode,
>  	ucode_hdr = (struct otx_cpt_ucode_hdr *) fw->data;
>  	memcpy(ucode->ver_str, ucode_hdr->ver_str, OTX_CPT_UCODE_VER_STR_SZ);
>  	ucode->ver_num = ucode_hdr->ver_num;
> -	ucode->size = ntohl(ucode_hdr->code_length) * 2;
> -	if (!ucode->size || (fw->size < round_up(ucode->size, 16)
> -	    + sizeof(struct otx_cpt_ucode_hdr) + OTX_CPT_UCODE_SIGN_LEN)) {
> +	code_length = ntohl(ucode_hdr->code_length);
> +	if (code_length >= INT_MAX / 2) {
> +		ret = -EINVAL;
> +		goto release_fw;
> +	}
> +	ucode->size = code_length * 2;
> +	if (!ucode->size ||
> +	    ucode->size > fw->size ||
> +	    (fw->size < round_up(ucode->size, 16) +
> +	     sizeof(struct otx_cpt_ucode_hdr) + OTX_CPT_UCODE_SIGN_LEN)) {
>  		dev_err(dev, "Ucode %s invalid size\n", ucode_filename);
>  		ret = -EINVAL;
>  		goto release_fw;
> -- 
> 2.35.1

Thanks,
-- 
Email: Herbert Xu <herbert@gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [PATCH] crypto: marvell/octeontx - prevent integer overflows

[Dan Carpenter]

On Thu, Sep 08, 2022 at 05:34:42PM +0800, Herbert Xu wrote:
> On Thu, Sep 01, 2022 at 06:32:09PM +0300, Dan Carpenter wrote:
> >
> > @@ -303,7 +304,13 @@ static int process_tar_file(struct device *dev,
> >  	if (get_ucode_type(ucode_hdr, &ucode_type))
> >  		return 0;
> >  
> > -	ucode_size = ntohl(ucode_hdr->code_length) * 2;
> > +	code_length = ntohl(ucode_hdr->code_length);
> > +	if (code_length >= INT_MAX / 2) {
> > +		dev_err(dev, "Invalid code_length %u\n", code_length);
> > +		return -EINVAL;
> > +	}
> > +
> > +	ucode_size = code_length * 2;
> >  	if (!ucode_size || (size < round_up(ucode_size, 16) +
> >  	    sizeof(struct otx_cpt_ucode_hdr) + OTX_CPT_UCODE_SIGN_LEN)) {
> >  		dev_err(dev, "Ucode %s invalid size\n", filename);
> 
> How come you didn't add a "ucode_size > size" check like you did
> below?
> 

I'm really sorry.  This was not my best work at all.  The ucode_size
was a mistake.  It should have just been the check against INT_MAX.

regards,
dan carpenter